Login using SSH into a new EC2 instance created from an custom AMI (image)

 Not able to login (SSH) to EC2 running Linux(Custom AMI)

Solution 

Login as ec2-user 

sudo su - root 

first use source *.pem key to login ec2 instance launch from custom AMI using ec2-user 

enable PasswordAuthentication to yes

vi /etc/ssh/sshd_config

PasswordAuthentication yes

systemctl restart sshd

then login with root user with same password as source.